forked from mirrors/gecko-dev
2d21b03a3b
FunctionTypeTraits< function type > makes it easier to inspect a function's return type, arity, and parameter types. It works with free functions, struct/class methods, function objects like non-generic lambdas and std::function. Differential Revision: https://phabricator.services.mozilla.com/D2998 --HG-- extra : moz-landing-system : lando
261 lines
7.2 KiB
C++
261 lines
7.2 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "mozilla/FunctionTypeTraits.h"
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#include <functional>
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using mozilla::FunctionTypeTraits;
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void
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f0()
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{
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}
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int
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f1(char)
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{
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return 0;
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}
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#ifdef NS_HAVE_STDCALL
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void NS_STDCALL
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f0s()
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{
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}
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int NS_STDCALL
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f1s(char)
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{
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return 0;
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}
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#endif // NS_HAVE_STDCALL
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struct S
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{
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void f0() {}
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void f0c() const {}
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int f1(char) { return 0; }
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int f1c(char) const { return 0; }
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#ifdef NS_HAVE_STDCALL
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void NS_STDCALL f0s() {}
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void NS_STDCALL f0cs() const {}
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int NS_STDCALL f1s(char) { return 0; }
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int NS_STDCALL f1cs(char) const { return 0; }
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#endif // NS_HAVE_STDCALL
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};
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(f0)>::ReturnType,
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void>::value,
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"f0 returns void");
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static_assert(FunctionTypeTraits<decltype(f0)>::arity == 0,
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"f0 takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(f0)>::template ParameterType<0>,
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void>::value,
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"f0 has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f0)>::ReturnType,
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void>::value,
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"S::f0 returns void");
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static_assert(FunctionTypeTraits<decltype(&S::f0)>::arity == 0,
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"S::f0 takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f0)>::template ParameterType<0>,
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void>::value,
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"S::f0 has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f0c)>::ReturnType,
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void>::value,
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"S::f0c returns void");
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static_assert(FunctionTypeTraits<decltype(&S::f0c)>::arity == 0,
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"S::f0c takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f0c)>::template ParameterType<0>,
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void>::value,
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"S::f0c has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(f1)>::ReturnType,
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int>::value,
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"f1 returns int");
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static_assert(FunctionTypeTraits<decltype(f1)>::arity == 1,
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"f1 takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(f1)>::template ParameterType<0>,
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char>::value,
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"f1 takes a char");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f1)>::ReturnType,
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int>::value,
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"S::f1 returns int");
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static_assert(FunctionTypeTraits<decltype(&S::f1)>::arity == 1,
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"S::f1 takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f1)>::template ParameterType<0>,
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char>::value,
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"S::f1 takes a char");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f1c)>::ReturnType,
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int>::value,
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"S::f1c returns int");
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static_assert(FunctionTypeTraits<decltype(&S::f1c)>::arity == 1,
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"S::f1c takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f1c)>::template ParameterType<0>,
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char>::value,
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"S::f1c takes a char");
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#ifdef NS_HAVE_STDCALL
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(f0s)>::ReturnType,
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void>::value,
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"f0s returns void");
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static_assert(FunctionTypeTraits<decltype(f0s)>::arity == 0,
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"f0s takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(f0s)>::template ParameterType<0>,
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void>::value,
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"f0s has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f0s)>::ReturnType,
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void>::value,
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"S::f0s returns void");
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static_assert(FunctionTypeTraits<decltype(&S::f0s)>::arity == 0,
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"S::f0s takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f0s)>::template ParameterType<0>,
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void>::value,
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"S::f0s has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f0cs)>::ReturnType,
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void>::value,
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"S::f0cs returns void");
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static_assert(FunctionTypeTraits<decltype(&S::f0cs)>::arity == 0,
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"S::f0cs takes no parameters");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f0cs)>::template ParameterType<0>,
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void>::value,
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"S::f0cs has no first parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(f1s)>::ReturnType,
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int>::value,
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"f1s returns int");
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static_assert(FunctionTypeTraits<decltype(f1s)>::arity == 1,
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"f1s takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(f1s)>::template ParameterType<0>,
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char>::value,
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"f1s takes a char");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f1s)>::ReturnType,
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int>::value,
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"S::f1s returns int");
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static_assert(FunctionTypeTraits<decltype(&S::f1s)>::arity == 1,
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"S::f1s takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f1s)>::template ParameterType<0>,
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char>::value,
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"S::f1s takes a char");
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static_assert(
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std::is_same<typename FunctionTypeTraits<decltype(&S::f1cs)>::ReturnType,
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int>::value,
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"S::f1cs returns int");
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static_assert(FunctionTypeTraits<decltype(&S::f1cs)>::arity == 1,
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"S::f1cs takes one parameter");
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static_assert(
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std::is_same<
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typename FunctionTypeTraits<decltype(&S::f1cs)>::template ParameterType<0>,
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char>::value,
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"S::f1cs takes a char");
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#endif // NS_HAVE_STDCALL
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template<typename F>
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void
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TestVoidVoid(F&&)
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{
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static_assert(
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std::is_same<typename FunctionTypeTraits<F>::ReturnType, void>::value,
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"Should return void");
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static_assert(FunctionTypeTraits<F>::arity == 0, "Should take no parameters");
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static_assert(
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std::is_same<typename FunctionTypeTraits<F>::template ParameterType<0>,
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void>::value,
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"Should have no first parameter");
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}
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template<typename F>
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void
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TestIntChar(F&&)
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{
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static_assert(
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std::is_same<typename FunctionTypeTraits<F>::ReturnType, int>::value,
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"Should return int");
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static_assert(FunctionTypeTraits<F>::arity == 1, "Should take one parameter");
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static_assert(
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std::is_same<typename FunctionTypeTraits<F>::template ParameterType<0>,
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char>::value,
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"Should take a char");
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}
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int
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main()
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{
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TestVoidVoid(f0);
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TestVoidVoid(&f0);
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TestVoidVoid(&S::f0);
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TestVoidVoid(&S::f0c);
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TestVoidVoid([]() {});
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std::function<void()> ff0 = f0;
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TestVoidVoid(ff0);
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TestIntChar(f1);
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TestIntChar(&f1);
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TestIntChar(&S::f1);
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TestIntChar(&S::f1c);
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TestIntChar([](char) { return 0; });
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std::function<int(char)> ff1 = f1;
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TestIntChar(ff1);
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#ifdef NS_HAVE_STDCALL
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TestVoidVoid(f0s);
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TestVoidVoid(&f0s);
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TestVoidVoid(&S::f0s);
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TestVoidVoid(&S::f0cs);
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std::function<void()> ff0s = f0s;
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TestVoidVoid(ff0s);
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TestIntChar(f1s);
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TestIntChar(&f1s);
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TestIntChar(&S::f1s);
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TestIntChar(&S::f1cs);
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std::function<int(char)> ff1s = f1s;
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TestIntChar(ff1s);
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#endif // NS_HAVE_STDCALL
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return 0;
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}
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